Speed reducer and reverse gear for internal-combustion engines



Nov. 10 1925.

G. FORNACA SPEED REDUCER AND REvERsE GEAR FOR INTERNAL COMBUSTION ENGINES Filed Sept. 25, 1924 accompanyin' Patented Nov. 10, 1925.

GUIDO FORNACA, OE TURIN, ITALY.

SPEED REDUCER AND REVERSE GEAR FOB INTERNAL-COMBUSTION ENGINES.

Application filed September asfiiu a Serial No. 739,887.

To all whom it may concern;

Be it known that 1, Gmno FommoA, a subject of the King of Italy, resident of Turin, in the Kingdom of Italy, have invented certain new and useful Improvements in Speed Reducers and Reverse Gears for Internal-Combustion Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the drawings, and to letters "or figures of re erence marked thereon, which form a part of this specification.

. It is known that in the construction of explosion engines for motor vehicles and boats, endeavours have been made to attain I high angular speeds, which allow of high specific power to be obtained. The propeller speed corresponding to highest efficiency has, however, considerably lower limits than that of the engines, so that it is necessary to employ speed reducers between the engine and the propeller shaft.

Moreover, when high power is aimed at, it is necessary to increase the number of cylinders of each engine and to install on board several engines. Each. engine has to be provided with a speed reducer and re" verse gear, thus rendering the arrangement clumsy, heavy and diiiicult in operation.

The present invention considerably simplifies the installation and improves the working thereof, by combining into a single unit the speed reducer and the reverse gear,- and serving by this unit several englnes, which, through suitable means also forming the object of the invention, can be grouped into a single block so that several. engines and a single reducer and reverse gear form a propelling unit. 4 The accompanying drawing shows by way. of example some constructional forms of the object of this invention.

Figure 1 shows a constructional form-for a single engine.

Figure 2 shows a constructional form for a double engine.

- Figures 3, 1 and 5, are relative and diagrammatic front views of the single, double and triple engine, respectively.

1 denotes an internal combustion engine of any suitable type, the crank shaft 2 whereof is provided at its end 3 with a on the shaft 7, which projects by its endlO into'a countershaft 11, on which it rests and within which it is free to rotate. The shaft 11 carries keys 12, projecting into corresponding keyways on the hub. 1415f a cone 13 The cone .13 is capable of longitudinal movement on the shaft 11 but the keys cause it to turn with this latter.

The hub 14 of the cone 13 carries at one end a circular groove 15 into which projects the forked end of a lever 16 secured to a shaft 17 on which is also fixed a lever 18 that can be brought into three different positions, namely 'two end positions 1920 indicated in hatched lines, and an intermediate one shown in full line. A casing 22 encloses all the mechanisms.

The shaft 11 is rigidlyconnected with the propeller shaft 23.

They device works as follows:

The mechanisms are supposed to be in the position shown in Fig. 1. The shaft 2 meshes by means of the pinion 4 with the wheel 5 and rim 6, thus imparting rotation in the same direction to the crank shaft 2 and rim 6 and in opposite direction to the wheel 5. The wheel 5 having a larger diameter than-the pinion 1, its revolution speed islessthan that of the crank-shaft 2. The rim 6 having a larger diameter than the wheel 5, also rotates'at a lower speed;

The cone 8 secured on the same shaft 7 same direction and at the same speed.

The cone 9 integral with the rim .6 rotates. in the samedirection and at the same speed as the rim. There are thus two cones 8 and 9 rotating in opposite directions and at different speeds. I

The cone 13 being' in the intermediate which carries the wheel 5 rotates in the By displacing the lever 18 to the position, indicated at 20, by means of lever 16 which follows the motion of lever 18 and projects into the groove 15, the hub 14 is caused to slide and the cone 13 is forced into the cone 8 and carried {along by this-latter at a speed equal to that of the wheel 5.

The motor boat thus oes ahead and the number of turns is re uced between the crank shaft and the propeller shaft in accordance with the difference between the diameters of the pinions 4" and 5. By displacing the lever 18 to the position indicated'at 19, by means of the lever 16 and hub 14 the cone 13 is disengaged from the cone 8 and is brought into engagement with the cone 9; this latter rotates in the direc-' tion opposite to the cone 8 and at 'a reduced speed with respect. to this latter; it therefore carries along the cone 13 with the shaft 11 and the propeller shaft 23.

The motorboat thus goes astern at a reduced propeller. speed.

The modified form shown. in Figure 2 refers to a double engine, wherein two crank shafts 2 are, provided with a pinion 4 meshing with the toothed rim 6 and gear 5.

The reducin and reverse gear serves in this case also or coupling the two engines. When it is desired to use one or both engines at will,- provision will be made for connecting or disconnecting the pinion 4 of each engine with or from the shaft by which it is supported. I,

lgure 5 shows a further modified form relatlng to a triple engine. The figure explains itself. Y

It is obvious that the object of the present invention can be used in connection with an type of boats or ships.

at I claim is:

1. The combination with a crank shaft, of

a driven shaft, an internally toothed gear .loose on the latter, a pinion fixed on the crank shaftin mesh with the internally toothed gear, a pinion fixed on the driven shaft in mesh with the pinion on the crank shaft, a conical clutch-member fixed on the driven shaft, a conical clutch member forming an integral extension of the internall toothed gear and surrounding the clutc member 'fixed on' the driven shaft, a counter shaft arranged axially of the driven shaft,

and an intermediate clutch member keyed to and movable axially on the counter shaft and having a conical portion interposed between tbe aforesaid clutch members adapted to be moved alternately into frictional engagement with the latter. a

2. Ina reversing mechanism for internal combustion engines, the combinati with a crank shaft, of a driven shaft ounted parallel to the latter, a toothed gear fixed on the driven shaft, an internally toothed gear loose on the latter, a pinion fixed on the crank shaftin mesh with the aforesaid gears, a conical clutch member forming an integral extension of the internally toothed gear, a conical clutch member fixed on the driven-shaft within said extension, a counter shaft having an axial recess in which the driven shaft is journaled, an intermediate clutch member rotatable with the counter shaft ,and having a conical portion interposed between the aforesaid clutch members, and means to move the intermediate clutch member axially of the counter shaft whereby it is brought alternately into frictional engagement with the other clutch members. y b

3. In a reversing mechanism, for internal combustion engines, the combination of a plurality of crank-shafts, a single casing in which the shafts are mounted, a driven shaft mounted parallel to and at equal distance from the crank-shafts and extending into a chamber formed in an extension of the easing, a combined speed reduction and reversing gearing connecting the driven shaft with the crank shaft and comprising a gear fixed on the driven-shaft, a 1nion fixed on each crank shaft in mesh with said gear, an internally toothed gear loosely mounted on the driven shaft and surrounding said gear and pinions and in mesh with the latter, a counter-shaft journaled in said extension and having an axial recess in one end forming a journal for one end of the driven shaft, a conical clutch member formingan integral extension of the externally toothed gear, a conical clutch member fixed on the riven shaft, and surrounded by said extension, an intermediate clutch member rotatable with the counter-shaft and having a conical portion extending between the aforesaid clutch members, and means for ,moving the intermediate clutch member axially of the latter, whereby it is brought alternately into frictional engagement with the other clutch members.

In testimony that I claim the foregoing .as my invention, I have signed my name.

eUIiio FORNAOA. 

